In recent years there has been an ever increasing demand for food products that can be prepared in a relatively short period of time in consumers' homes and various retail establishments such as so-called "fast food" restaurants. One particular group of popular foods is deep-fried foods such as french fries, battered vegetables such as onion rings, mushrooms, zucchini, etc., and battered meats such as fish sticks and patties, chicken nuggets, etc. In a typical commercial deep-frying operation, a large quantity of the food product is removed from its bulk shipping container and placed within a wire mesh basket that is lowered into a large vat of hot cooking oil or grease. After the food product has been immersed in the hot oil for several minutes, the basket is removed from the vat and set aside to allow the food product to cool and excess oil to drain therefrom. Individual servings of the food product are then placed within containers which are typically open-ended cardboard pouches for french fries, or closable card-board boxes for fish and chicken parts. Generally speaking, most people find food products prepared and packaged in this fashion to be very satisfactory.
There have been numerous attempts at making deep-fried food products available at places other than restaurants such as consumers' homes, convenience stores, vending machine canteens, cafeterias, etc. However, it has been found that providing and maintaining the necessary reservoir of hot oil presents many major problems. For example, the hot oil may splatter when the food product is immersed therein which not only creates a mess but can fall on the operator's skin and cause a burn. Also, the oil can sometimes become too hot and possibly ignite. Furthermore, the oil must be changed frequently due to contamination and spoilage. Finally, the fumes emitted from the cooking oil should be vented, preferably to the outside atmosphere, which requires additional equipment and associated costs.
Another common method of heating or cooking food products is to simply place the food on a pan or similar utensil and place it within a conventional oven. However, the food product's unexposed surfaces, i.e., the surfaces that touch the pan or one another, are not in direct contact with the hot air and consequently the food is not evenly cooked or crisped. A common solution to this problem involves periodically opening the oven's door and moving the food product around in the pan. However, this method is time consuming and therefore impractical, particularly in a restaurant or convenience store environment where labor costs are of primary concern. Moreover, each time the oven door is opened, a considerable amount of the hot air escapes, which drives up energy costs and significantly increases the already lengthy cooking time.
Another known method of heating or cooking food products involves using microwave ovens, which have become very popular in consumer's home and retail establishments primarily because the oven's cooking time is typically very short. While the microwave oven has proved to be imminently satisfactory for rapidly heating many different types of food products, it is apparently not entirely suitable for cooking other types of food products, most notably foods that are typically deep-fried such as french fries. Indeed, most french fries that are prepared by using a microwave oven turn out to be rubber, lack crispness and good texture, and are generally wholly unacceptable.
Others have recognized a need for an oven apparatus that can be used to cook a food product such as french fries in a convenient and rapid manner. For example, U.S. Pat. No. 3,870,193 to Schneider; U.S. Pat. No. 4,155,294 to Langhammer et al.; and U.S. Pat. No. 4,491,065 to Poulson disclose various ovens for heating and dispensing french fries that generally include a rotatable cage that is filled with fries which are cooked by passing heated air through the cage. However, it has been found that this general type of oven is somewhat inconvenient and unsanitary to use because it must be manually loaded with fries from a bulk source, and manually unloaded. In addition, since the fries come into direct contact with the cage, the cage must be regularly cleaned and sanitized. Finally, in the case of the Schneider oven, a relatively complicated and presumably expensive drive system is included that moves the heating cage between a loading position, a heating position, and a delivery position.
Another type of oven is disclosed in U.S. Pat. Nos. 4,375,184 and 4,397,875 both to Gilliom. This oven heats french fries by essentially blowing hot air on the fries while they rest on top of a tray-type container. However, it has been found that this general type of oven and receptacle arrangement does not produce acceptable fries. Specifically, since the fries remain piled up on top of one another during the heating process, the fries become overly crisped in areas that are exposed to the heated air and essentially raw in areas that are in contact with the receptacle or with an adjacent fry.
A major concern associated with heating foods such as pre-cooked french fries that is not adequately addressed by prior attempts including the ovens discussed above is the fumes generated during the heating process. Generally speaking, when pre-cooked fries are initially prepared, oil is used which leaves a residual amount of oil on the fry's outer surfaces. When the fries are heated with hot air, some of the surface oil's more volatile elements vaporize with some undergoing partial combustion. These smoke-like gaseous and particulate products inevitably accumulate on the inner surfaces of the oven and therefore require the oven to be frequently cleaned and maintained. If the fumes are simply vented outside the oven as most known ovens suggest, the room rapidly becomes filled with fumes which can leave a film of oil on the room's walls, floor, and ceiling and can also leave an odor that can last for several days.
In light of the above, the principle object of the present invention is to provide a method of and apparatus for heating or cooking various food products in a relatively short period of time such that they are appetizing and have good texture and appearance.
Another principle object of the present invention is to provide a fast, efficient, and sanitary method of and apparatus for heating/cooking various food products without having to remove the food from its shipping container.
Another principle object of the present invention is to provide a method of and apparatus for rapidly heating a food product in a container while ensuring even heating of the food.
Yet another object of the present invention is to provide a method of and apparatus for heating a food product wherein the product does not come into direct contact with any of the apparatus' internal components.
A further object of the present invention is to provide a method of and apparatus for heating a food product that includes a control system that compensates for the initial state of the oven and the food product, e.g., chilled or frozen.